Panasonic TC-L42D2 Technical Manual page 84

Conclusion: Exchange the Panel
Source Driver
LCD Panel (Gate Driver is in Panel)
Diagnosis
In this case , a small horizontal line problem is the LCD panel defect.
If IC8001 Nile-TCON is defective, there would be many horizontal lines all over
screen.
Picture Defect (4) (D Series)
Gate
Driver
LVDS DATA
Control DATA
TC board
LVDS DATA
A board
(LVDS= Low Voltage Differential Signaling)
Sample Picture
Abnormal lines
Abnormal line
Slide # 84